Immunocompromised Covid booster?

[inhomich]

I have heard that a few doctors are recommending COVID boosters for immunocompromised patients, and that some individuals have taken it upon themselves to take an additional shot. With the sparse data and complete lack of coverage on this, I’m wondering if anyone with experience and expertise in this realm can contribute to the discussion. 
 

Specifically, for a patient overall in good health and on immunosuppressives s/p double lung transplant  2013, who has received two doses of Pfizer vaccine and subsequently tested negative for antibodies via rapid blood antigen test 1 month post second dose. My inclination would be to recommend a third/ booster of Moderna. Thoughts? 
 

I know the ACIP is meeting soon but I don’t expect any update on this segment. Blanket recommendations are largely to entirely useless and non applicable for this population subgroup. 
 

Thanks for your time.